Instantly the earthquake appears in that place and those monsters begin to take damage from that. As you know even though fighters could feel the earthquake but none of them were able to take damage from that because he was now only targeting those Monsters. Only those people will receive damage that he targeted while using the technique.
This also gives those fighters time to move away from that place as every one of them begins to make distance from those Monsters. All of them know that most likely Alex is going to use his powerful techniques and because of these none of them wanted to be affected by that. Actually everyone of them did the right thing because in the next second many tornadoes appeared in that place and those monsters instantly began to pull in those tornadoes.